The Wiert Corner - irregular stream of stuff: jpluimers

A bit more than a year ago, I wrote about Delphi: you should avoid the `with` statement as it makes your code less future proof. That caused some nice comments on the blog, and some more on LinkedIn where Paul Foster mentioned it in a thread ‘Jeoren Pluimers makes a case against “with” statements.‘ Both interesting reads, especially the reasons that people use or avoid with, or keep its use in balance. There is one set of comments I want to emphasize: refactoring multiple with statements into a one function and a call per former with.

Mark Stolworthy: I think when used simply the code becomes easier to read ?

with pdata do
begin
  DatabaseName := pDB.databasename;
  TableName := 'Xdata';
  readonly:=Preadonly;
  FieldDefs.clear;
  IndexDefs.clear;
end;

with pitem do
begin
  DatabaseName := pDB.databasename;
  TableName := 'Xitem';
  readonly:=Preadonly;
  FieldDefs.clear;
  Indexdefs.clear;
end;

I disagree with code like that, as it is very easily refactored into something like this:

Jeroen Pluimers• @Mark, Your code should be refactored to use a method, similar to the example at http://wiert.me/2013/03/27/delphi-you-should-avoid-the-with-statement-as-it-makes-your-code-less-future-proof/#comment-17355 Also if this is from production code, you should use code-completion to make sure the casing of the members is correct.

Initialize(PData, pDB, 'Xdata', PReadOnly);
Initialize(PItem, pDB, 'Xitem', PReadOnly);

procedure TMyClass.Initialize(MyDataSet: TMyDataSet; MyDataBase: TMyDatabase; string TableName; ReadOnly: Boolean);
begin
  MyDataSet.DatabaseName := MyDataBase.DataBaseName;
  MyDataSet.TableName := TableName;
  MyDataSet.ReadOnly := ReadOnly;
  MyDataSet.FieldDefs.Clear();
  MyDataSet.IndexDefs.Clear();
end;

–jeroen

PS: funny to see I officially hate hate hate the WITH statement got posted this week too, as my post above had been in the blog queue more than a year ago: since 20130505 (: